In the field of data processing, the personal or pocket-type calculator has enjoyed success by individual users for performing various types of financial transactions. It is common practice and procedure to use the calculator for performing a number of arithmetic and like functions and it is also seen that additional or related functions are feasible when using these small portable units. The portable units or terminals are useful in a "cashless" environment wherein banking and/or retail transactions can be continually processed and updated to reflect the current status of one or more accounts.
While it is seen that many of the early pocket calculators had limited capabilities in number and type of functions, later units have included means for accomplishing such additional functions as well as connecting or interfacing with peripheral or related equipment in time saving and lower cost operations.
Representative documentation in the field of calculators and control means therefor includes U.S. Pat. No. 3,548,160, issued to W. B. Welsh on Dec. 15, 1970, which discloses apparatus with means for receiving a record containing fixed data in the form of a code as well as variable data input from a keyboard, and wherein the fixed and the variable coded data are of the same form and are scanned to produce output signals which can be inserted in the data processing system.
U.S. Pat. No. 4,017,835, issued to R. D. Randolph on Apr. 12, 1977, discloses a credit status verification system having input terminals along with a central terminal unit connected to send and receive messages in a computer system.
U.S. Pat. No. 4,053,735, issued to J. N. Foudos on Oct. 11, 1977, discloses a portable unit for receiving credits for checks relative to a bank assured-check computer-based credit disbursing system.
U.S. Pat. No. 4,091,270, issued to B. E. Musch et al. on May 23, 1978, discloses a portable, electronic, keyless calculator with an optical bar code reader, a read-write memory unit for storing the entered information, a central processing unit having a read-only memory with pre-stored routines, and a display unit for displaying entered data and execution results. An alternative embodiment of the calculator includes both an optical bar code reader and a keyboard as input devices for entering data.
U.S. Pat. No. 4,208,575, issued to G. P. Haltof on Jun. 17, 1980, discloses a credit card or check validator which includes a keyboard, a scrambler circuit and a comparator circuit.
U.S. Pat. No. 4,219,151, issued to T. Haruki on Aug. 26, 1980, discloses a verification system having reading means to read first data from a card, input means manually operable to enter second data different from the first data, function storage means for different functions, calculating means for calculating a functional value, and checking means for checking relationship between a portion of the data and the calculated value.
U.S. Pat. No. 4,277,837, issued to P. E. Stuckert on Jul. 7, 1981, discloses a portable terminal or calculator for use with one or more data storage and transfer cards, and including keyboard means for entering data and control information, means for temporarily storing transaction data, and logic means for performing arithmetic, logical, and control operations, and also means for storing predetermined programs. Display means selectively displays transaction data and selected data is transferred into storage means in an external device and into at least one card. One or more of such data storage and transfer cards can be inserted into a slot position on the bottom of the calculator and transfer of data may take place between the card and the calculator or between two cards and the calculator, dependent, in part, on the movement of one or another card to one of several positions.
And, U.S. Pat. No. 4,523,297, issued to M. Ugon et al. on Jun. 11, 1985, discloses a portable hand-held data processor having a keyboard, a display and a slot for a removable card. A first microprocessor and a first memory are connected to the keyboard and the display, and a second microprocessor and a second memory are included in the card with a single line connecting the first and the second microprocessors and memories.